Two-Way Wobble Plate Compressor

ABSTRACT

A two-way wobble plate compressor, comprising: a cylinder block ( 100 ); a two-way piston ( 200 ) capable of reciprocating within a cylinder bore ( 110 ) of the cylinder block ( 100 ); a drive assembly ( 300 ) driving the two-way piston ( 200 ), the drive assembly ( 300 ) including a drive shaft ( 310 ), a rotor ( 320 ) fixedly connected with the drive shaft ( 310 ), and an annular wobble plate ( 330 ) fitting with the rotor ( 320 ); the rotor ( 320 ) has an inner surface ( 323 ) for fitting with the annular wobble plate ( 330 ), the inner surface ( 323 ) include a first inner surface ( 324 ) and a second inner surface ( 325 ), which are oppositely arranged, and a rotor contact surface ( 326 ); the wobble plate ( 330 ) is partially encircled within the inner surface ( 323 ) of the rotor ( 320 ), and includes a first peripheral portion ( 334 ), a second peripheral portion ( 335 ), and a wobble plate contact surface ( 336 ); a first bearing ( 340 ) is provided between the first inner surface ( 324 ) and the first peripheral portion ( 334 ), a second bearing ( 350 ) is provided between the second inner surface ( 325 ) and the second peripheral portion ( 335 ), and a third bearing ( 360 ) is provided between the rotor contact surface ( 326 ) and the wobble plate contact surface ( 336 ). The two-way wobble plate compressor of the present invention may significantly reduce friction loss.

TECHNICAL FIELD

The present invention relates to a wobble plate compressor having atwo-way piston.

BACKGROUND ART

Traditional compressors include swash plate compressors. Usually, aswash plate type compressor includes a drive shaft, a swash plateconnected together with the drive shaft, and several pistons operativelyconnected with the swash plate. When a drive unit drives the drive shaftto rotate in a well-known manner, the swash plate will bring each pistonwithin cylinders into reciprocating motion.

For example, U.S. Pat. No. 5,009,574 discloses a traditional swash platecompressor, in the structure of which a swash plate is fixedlyintegrated on a drive shaft, such that the swash plate rotates togetherwith the drive shaft. In other words, the swash plate does not rotaterelative to the drive shaft. During the operation of a traditional swashplate compressor, the piston simply performs reciprocating motion. Insuch a structure, it further includes a sliding shoe, through which theswash plate drives the piston into reciprocating motion. Since the swashplate rotates together with the drive shaft, it causes high speedsliding motion between each sliding shoe and the swash plate.

The characteristic high speed sliding motion between the sliding shoeand the swash plate within the swash plate compressor may result in highfriction loss and low loading capacity, and particularly, thecircumstances become more serious in large volume compressors. Thus, asan improvement to swash plate compressors, wobble plate compressors inthe prior art disengage the motion of the swash plate from the driveshaft, trying to reduce the above described friction loss.

For example, U.S. Pat. No. 2,335,415 discloses a wobble plate compressorstructure, and in this structure, a wobble plate is connected to a hubof a drive shaft via an anti-friction bearing, such that the wobbleplate performs wobbling motion without rotating together with the driveshaft; in other words, there is only slight sliding motion between thewobble plate and the sliding shoe, and sliding friction with high speedmotion between the traditional swash plate and the sliding shoe has beenreplaced by rolling friction of the bearing. However, the structurereduces friction loss, but it is not compact enough, and lacksindustrial applicability.

U.S. Pat. No. 5,239,913 discloses another typical wobble platecompressor structure. In this structure, a force from a top of thepiston is directed to a bearing via a connecting rod and the wobbleplate; for compressors using a single-way piston, such a wobble platestructure is conventionally usable, however, for larger volumecompressors requiring a two-way piston, this structure is obviously notsuitable, because there is totally no sufficient space for mounting thebearing and the connecting rod at a same position.

In addition, in this and similar structures, the wobble plate isconnected with each piston via a piston rod. Thus, in this piece ofprior art, it essentially requires a wobble plate stopper to stop thewobble plate from rotating, which makes the compressor structurecomplicated, resulting in a uneven or unbalanced, complicated manner ofrotation, which in turn produces vibrations and noises.

Thus, a novel wobble plate compressor structure is needed, which may, atthe same time of maintaining its applicable range, reduce friction loss,improve energy conversion efficiency, and meanwhile overcome the abovedescribed problems of existing wobble plate structures.

SUMMARY OF THE INVENTION

An object of the present invention is to overcome the above describeddisadvantages of the existing wobble plate compressor structures,thereby providing a novel wobble plate compressor structure with lowfriction loss, and improved energy conversion ratio.

In order to achieve the above described object, the present inventionprovides a two-way wobble plate compressor, comprising:

a cylinder block, the cylinder block having a cylinder bore;

a two-way piston capable of reciprocating within the cylinder bore ofthe cylinder block;

a drive assembly driving the two-way piston, the drive assemblyincluding a drive shaft, a rotor fixedly connected with the drive shaft,and an annular wobble plate fitting with the rotor, the rotor having acentral plane angled to a perpendicular plane of the drive shaft, thecentral plane of the wobble plate being coincident with the centralplane of the rotor, when the drive shaft rotates, the rotor drives thetwo-way piston via the wobble plate to perform reciprocating motion;particularly,

the rotor has an inner surface for fitting with the annular wobbleplate, the inner surface including a first inner surface and a secondinner surface, which are oppositely arranged, and a rotor contactsurface arranged between the first inner surface and the second innersurface;

the wobble plate is partially encircled within the inner surface of therotor, and includes respectively a first peripheral portion adjacent tothe first inner surface, a second peripheral portion adjacent to thesecond inner surface and opposite to the first peripheral portion, and awobble plate contact surface adjacent to the rotor contact surface andarranged between the first peripheral portion and the second peripheralportion;

wherein a first bearing is provided between the first inner surface andthe first peripheral portion, a second bearing is provided between thesecond inner surface and the second peripheral portion, and a thirdbearing is provided between the rotor contact surface and the wobbleplate contact surface.

Alternatively, an inner ring contact surface and an outer ring contactsurface of said first bearing are respectively in contact with the firstinner surface and the first peripheral portion;

An inner ring contact surface and an outer ring contact surface of saidsecond bearing are respectively in contact with the second inner surfaceand the second peripheral portion; and

An inner ring contact surface and an outer ring contact surface of saidthird bearing are respectively in contact with the rotor contact surfaceand the wobble plate contact surface.

Preferably, a thrust washer is provided between the inner ring contactsurface of said first bearing and said first inner surface, and/orbetween the outer ring contact surface of said first bearing and saidfirst peripheral portion; and

A thrust washer is provided between the inner ring contact surface ofsaid second bearing and said second inner surface, and/or between theouter ring contact surface of said second bearing and said secondperipheral portion.

Said first bearing and the second bearing each is one of a needle rollerthrust bearing, a roller pin thrust bearing, alternatively a double rowneedle roller thrust bearing, a double row roller pin thrust bearing,and a conical roller thrust bearing.

Said third bearing is one of a radial needle roller bearing,alternatively a radial roller pin bearing, or a radial ball bearing.

Preferably, a thrust washer is provided between the inner ring contactsurface of said second bearing and said second surface, and between theouter ring contact surface of said second bearing and said secondperipheral portion, and said third bearing is a radial ball bearing.

Preferably, said two-way piston includes two socket portions, twohemispherical sliding shoes are provided within the two socket portionsfor interacting with the first peripheral portion and the secondperipheral portion of said wobble plate, respectively.

Preferably, said rotor includes a first annular flange and a secondannular flange, and the first annular flange and the second annularflange are fastened together via a nut and said drive shaft.

As compared with the prior art, the wobble plate compressor of thepresent invention is of a compact structure with low design complexity,which improves efficiency and output power, and at the same time, costcan be successfully controlled, so it is suitable for application incommercial compressors.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of an embodiment of a two-way wobble platecompressor of the present invention;

FIG. 2 is a partially enlarged illustrative view of the embodiment ofFIG. 1;

FIG. 3 is another partially enlarged illustrative view of the embodimentof FIG. 1;

FIG. 4 is an illustrative view of a second embodiment of the presentinvention, which uses a double row needle roller or double row rollerpin thrust bearing;

FIG. 5 is an illustrative view of a third embodiment of the presentinvention, which uses a conical roller thrust bearing;

FIG. 6 is an illustrative view of a fourth embodiment of the presentinvention, which uses an angled needle roller or roller pin thrustbearing;

FIG. 7 is an illustrative view of a fifth embodiment of the presentinvention, which uses an angled double row needle roller or double rowroller pin thrust bearing;

FIG. 8 is an illustrative view of a sixth embodiment of the presentinvention, which uses a conical roller thrust bearing;

FIG. 9 is an illustrative view of a seventh embodiment of the presentinvention, which uses a thrust washer on a contact surface at one sideof the bearing;

FIG. 10 is an illustrative view of an eighth embodiment of the presentinvention, which uses a thrust washer on a contact surface at the otherside of the bearing;

FIG. 11 is an illustrative view of a ninth embodiment of the presentinvention, which uses a thrust washer on contact surfaces at both sidesof the bearing; and

FIG. 12 is an illustrative view of a tenth embodiment of the presentinvention, which uses a ball bearing.

DETAILED DESCRIPTION OF THE EMBODIMENTS

With reference to particular embodiments and corresponding drawings, thestructure composition and the operating principles of a two-way wobbleplate compressor of the present invention will be described in detail inthe following.

Generally speaking, the two-way wobble plate compressor of the presentinvention adopts a two-way piston structure, which uses a wobble plateto drive a two-way piston to reciprocate, and motion of the wobble plateis driven by a rotor fixed on a drive shaft. The present invention isparticularly characterized by the manner of fitting between the wobbleplate and the rotor. Bearing(s) may be fit between the wobble plate andthe rotor so as to form a combined bearing unit; in other words, inaddition to operating to drive the two-way piston into motion, thewobble plate may also directly serve as the outer ring of the combinedbearing unit; and in addition to operating to drive the wobble plateinto wobbling motion, the rotor mounted on drive shaft may also directlyserve as the inner ring of the combined bearing unit. As such, highspeed sliding motion in traditional swash plate compressors is replacedby rolling motion of the combined bearing unit; and meanwhile, ascompared with the prior art, the wobble plate compressor of the presentinvention is of a compact structure with low design complexity, whichimproves efficiency and output power, and at the same time, cost can besuccessfully controlled, so it is suitable for application in commercialcompressors.

Specifically, in FIG. 1, an illustrative view of an embodiment of atwo-way wobble plate compressor of the present invention is shown.

With reference to the drawing, in this embodiment, the two-way wobbleplate compressor includes a cylinder block 100, the cylinder blockhaving several cylinder bores 110. Conventionally, the cylinder block100 consists of a front cylinder block 120 and a rear cylinder block130, and includes a pair of central holes 140 along a longitudinal axis0-0 of the cylinder block; and the cylinder bores 110 are evenlyarranged around the central hole 140.

The two-way wobble plate compressor further includes several two-waypistons 200 capable of reciprocating in the cylinder bores 110 of thecylinder block 100. The two-way pistons 200 perform reciprocating motionin relevant cylinder bores 110 of the front cylinder block 120 and therear cylinder block 130.

The two-way wobble plate compressor further includes a drive assembly300 driving the two-way pistons 200, the drive assembly 300 including adrive shaft 310, a rotor 320 fixedly connected with the drive shaft 310,and an annular wobble plate 330 fitting with the rotor 320; and furtherwith reference to FIGS. 2 and 3, the rotor 320 has a central plane P-Pangled to a perpendicular plane I-I of the drive shaft 310 at an angleof a, the central plane of the wobble plate 330 is coincident with thecentral plane P-P of the rotor 320, and when the drive shaft 310rotates, the rotor 320 drives the two-way piston 200 into reciprocatingmotion via the wobble plate 330.

Conventionally, the drive shaft 310 is rotatably arranged the centralhole 140 of the front cylinder block 120 and the rear cylinder block130, and may be driven into rotation by an external driving force. Therotor 320 is fixedly connected with and integrated on the drive shaft,so it may rotate along with the rotation of the drive shaft 310.Further, with reference to FIGS. 2 and 3, the rotor 320 mayconventionally consist of a first annular flange 321 and a secondannular flange 322. The first annular flange 321 may be fixed on a boss311 of the drive shaft 310, and similarly, the second annular flange 322may be fixed to an engaging surface 3212 of the first annular flange 321and the drive shaft 310; and the first annular flange 321 and the secondannular flange 322 are fastened together via a nut 312 and the driveshaft 310, thereby realizing a fixed connection of the rotor 320 and thedrive shaft 310. Of course, in an embodiment of the present invention,the fixed connection of the rotor 320 and the drive shaft 310 may alsobe implemented in other well known manners. As described above, thecentral plane P-P of the rotor 320 and the perpendicular plane I-I ofthe drive shaft 310 form an included angle α. The included angledetermines a stroke length when the two-way piston 200 performsreciprocating motion.

Particularly, with reference to FIGS. 2 and 3, the rotor 320 has aninner surface 323 for fitting with the wobble plate 330; in theembodiment, two inner surfaces 323 are provided between the firstannular flange 321 and the second annular flange 322. The inner surface323 include a first inner surface 324 and a second inner surface 325,which are oppositely arranged, and a rotor contact surface 326 arrangedbetween the first inner surface 324 and the second inner surface 325.

The wobble plate 330 is partially encircled within the inner surface 323of the rotor 320, and includes respectively a first peripheral portion334 adjacent to the first inner surface 324, a second peripheral portion335 adjacent to the second inner surface 325 and opposite to the firstperipheral portion 334, and a wobble plate contact surface 336 adjacentto the rotor 320 contact surface and arranged between the firstperipheral portion 334 and the second peripheral portion 335.

As a most prominent feature of the present invention, a first bearing340 is provided between the first inner surface 324 and the firstperipheral portion 334; a second bearing 350 is provided between thesecond inner surface 325 and the second peripheral portion 335; and athird bearing 360 is provided between the rotor contact surface 326 andthe wobble plate contact surface 336.

More specifically, as shown in FIG. 3, the first peripheral portion 334of the wobble plate 330 includes an upper surface 3341 and a lowersurface 3342 arranged on an upper portion of the wobble plate, andcorrespondingly, the second peripheral portion 335 of the wobble plate330 includes an upper surface 3351 and a lower surface 3352 arranged onthe upper portion of the wobble plate. As shown in the figures,specifically, the first bearing 340 is arranged between the first innersurface 324 and the lower surface 3342 of the first peripheral portion,and the second bearing 350 is arranged between the second inner surface325 and the lower surface 3252 of the second peripheral portion. In theillustrated embodiment, the upper surface 3341 and the lower surface3342 of the first peripheral portion 334, and the upper surface 3351 andthe lower surface 3352 of the second peripheral portion 335 arerespectively arranged in different planes, that is to say, the firstperipheral portion 334 and the second peripheral portion 335 arerespectively a stepped surface. However, it will be easily understoodthat, their respective upper surface and lower surface may bealternatively arranged in a same plane.

As shown in FIGS. 1, 2, and 3, in an embodiment of the presentinvention, the first bearing 340 directly acts on the first innersurface 324 and the first peripheral portion 334; the second bearing 350directly acts on the second inner surface 325 and the second peripheralportion 335; and the third bearing 360 directly acts on the rotorcontact surface 326 and the wobble plate contact surface 336. In otherwords, for the first bearing 340, the first bearing 340 includes anouter ring contact surface 341 and an inner ring contact surface, andits outer ring contact surface 341 and the first peripheral portion 334of the wobble plate 330 coincide, and its inner ring contact surface andthe first inner surface 324 of the rotor 320 inner surface 323 coincide;for the second bearing 350, its outer ring contact surface 351 and thesecond peripheral portion 335 of the wobble plate 330 coincide, and itsinner ring contact surface and the second inner surface 325 of the rotor320 inner surface 323 coincide; and for the third bearing 360, its outerring contact surface and the wobble plate contact surface 336 of thewobble plate 330 coincide, and its inner ring contact surface and therotor contact surface 326 of the rotor 320 inner surface 323 coincide.

With reference to FIGS. 1, 2, and 3, traditional sliding shoe fittingstructure may be adopted for the fittingly driving of the wobble plate330 and the two-way piston 200. Specifically, the two-way piston 200includes a plurality of socket portions 210, each socket portion 210being a hemispherical concave surface respectively provided along anaxial direction A-A of the two-way piston 200 and the front and rearwalls 221 of the slot 220 at a middle portion of the two-way piston 200.Further, two hemispherical sliding shoes 230 are respectively providedin the socket portions 210 for interacting with the first peripheralportion 334 and the second peripheral portion 335 of the wobble plate330. Specifically, the two hemispherical sliding shoes 230 arerespectively interacting with the wobble plate 330 via the upper surface3341 of the first peripheral portion 334 and the upper surface 3351 ofthe second peripheral portion 335. Conventionally, a flat part of thehemispherical sliding shoe 230 is defined as a flat portion 231, and aprojected surface part is defined as a convex portion 232; and thesliding shoe 230 may serve as a pivot bearing part between theperipheral portion of the wobble plate 330 and the socket portion 210 ofthe two-way piston 200. Thus, the wobble plate 330 may be sphericallyhinged to the two-way piston 200 via the socket portion 210 and thehemispherical sliding shoe 230.

Of course, it will be easily understood that, the wobble plate 330 mayalso drive the two-way piston 200 into reciprocating motion by otherconventional fitting means, for example, using a pin structure toimplement a fitting connection between the wobble plate 330 and thetwo-way piston 200.

As such, when the peripheral portion of the wobble plate 330 slidinglypasses between two flat portions of a pair of sliding shoes 230, and thesliding shoe 230 is provided between the two-way piston 200 and thewobble plate 330, the two-way piston 200, the sliding shoe 230, and theperipheral portion wobble plate 330 collectively form a universalbearing structure, and in the present embodiment, the universal bearingstructure is a sliding shoe universal joint structure.

In the embodiment, when the drive shaft 310 of the wobble platecompressor rotates, the rotor 320 will rotate with the rotation of thedrive shaft 310; due to the actions of the first bearing 340, the secondbearing 350, and the third bearing 360, the wobble plate 330 performswobbling motion but does not rotate along with the rotation of the driveshaft; due to the actions of the sliding shoe universal joint, the flatportion of the sliding shoe 230 and the peripheral portion of the wobbleplate 330 move up and down with respect to each other in a diameterdirection relative to wobble plate 330; and the two-way piston 200performs forward and rearward reciprocating motion under the constraintsof the corresponding cylinder bore in the cylinder block 100. Sincethere is no constraint on the rotation of the wobble plate 330, when thedrive shaft 310 rotates, the wobble plate 330 may alsodisproportionately and slowly rotate along with the rotation of thedrive shaft 310 under the actions of friction forces of the firstbearing 340, the second bearing 350, and the third bearing 360, and suchrotation will greatly reduce wear between surfaces of the peripheralportion of the wobble plate 330 and the flat portion of the sliding shoe230.

Further, with reference to FIGS. 2 and 3, a force Fl coming from thetwo-way piston 200 and acting on the sliding shoe 230 is transmitted tothe first bearing 340 and the second bearing 350 via the wobble plate330, but the force bearing point of Fl falls out of the inner ringcontact surfaces 324, 325 of the first bearing 340 and the secondbearing 350. In order to prevent such circumstances from happening, aforce F2 directed to the centers of the first bearing 340 and the secondbearing 350 is applied thereto in advance via tightening of the nut 312,such that the magnitude, direction and force bearing point of aresultant force F of F1 and F2 is changed. This makes it possible tooptimally comply with the design and use requirements of the bearings,and may greatly lengthen the service lives of the bearings.

In the above described embodiments, the first bearing 340 and the secondbearing 350 are needle roller thrust bearings; however, alternatively,the first bearing and the second bearing each may also be one of aroller pin thrust bearing, a double row needle roller thrust bearing, adouble row roller pin thrust bearing, and a conical roller thrustbearing. Similarly, in the above described embodiments, the thirdbearing 360 is a radial needle roller bearing; however, alternatively,the third bearing 360 may also be a radial roller pin bearing or aradial ball bearing.

For example, in the embodiment as shown in FIG. 4, the first bearing 340and the second bearing 350 are double row needle roller thrust bearingsor double row roller pin thrust bearings. In the embodiment as shown inFIG. 5, the first bearing 340 and the second bearing 350 are conicalroller thrust bearings. Here, the outer ring contact surfaces 341, 351and the inner ring contact surfaces 342, 352 of the first bearing 340and the second bearing 350, both of conical roller thrust bearing type,respectively coincide with two peripheral surfaces of the wobble plate330 and the first inner surface and the second inner surface of therotor inner surface, both of which have a same cone angle δ, and a sizeof the cone angle δ may be determined according to design requirementsfor the conical roller thrust bearing.

As shown in FIG. 6, in another alternative embodiment, the first bearing340 and the second bearing 350 are similar to those in the firstembodiment as shown in FIGS. 1-3, using needle roller thrust bearings orroller pin thrust bearings, however, they differ in the directions ofthe roller axes. In this embodiment, there is an angle β from 0 degreeto ±12 degrees between the roller axis and a central plane of the rotor320. Considering this design requirements, in the present embodiment,similarly, the outer ring contact surface 341 of the first bearing 340and the first peripheral portion of the wobble plate 330 coincide, andthe inner ring contact surface 342 of the first bearing 340 and thefirst inner surface of the rotor inner surface coincide, such that thetwo contact surfaces are parallel relative to the axis of the bearingrollers. FIG. 7 is a variant of the embodiment of FIG. 6, which differsfrom FIG. 6 in that the first bearing 340 and the second bearing 350 inFIG. 7 are double row needle roller or double row roller pin thrustbearings.

As shown in FIG. 8, as compared with the embodiments of FIGS. 6 and 7,the first bearing 340 and the second bearing 350 may also be implementedas conical roller thrust bearings. In the embodiment, the outer ringcontact surfaces 341, 342 and the inner ring contact surfaces 351, 352of the two conical roller thrust bearing 340, 350 respectively coincidewith the two peripheral portions of the wobble plate 330 and the firstinner surface and the second inner surface of the rotor inner surface,both of which have a same cone angle γ, and a size of the cone angle γmay be determined according to design requirements for conical rollerthrust bearings.

Preferably, in an alternative embodiment, a thrust washer is providedbetween the inner ring contact surface of the first bearing 340 and thefirst inner surface 324, and/or between the outer ring contact surfaceof the first bearing 340 and the first peripheral portion 334; and athrust washer is provided between the inner ring contact surface of thesecond bearing 350 and the second inner surface 325, and/or between theouter ring contact surface of the second bearing 350 and the secondperipheral portion 335. With reference to FIG. 9, a thrust washer 370 isprovided between the first bearing 340 and the first inner surface, andbetween the second bearing 350 and the second inner surface,respectively. The thrust washer 370 is configured such that specialtreatment on the inner surface of the rotor may be avoided, therebyfurther reducing cost. With reference to FIG. 10, in the embodiment, athrust washer 370 is provided between the first bearing 340 and thefirst peripheral portion of the wobble plate 330, and between the secondbearing 350 and the second peripheral portion of the wobble plate 330,respectively. With reference to FIG. 11, in the embodiment, a thrustwasher 370 is provided on both an outer side of the two contact surfacesof the first bearing 340 and an outer side of the two contact surfacesof the second bearing 350.

In addition, with reference to FIG. 12, alternatively, the third bearing360 may also be a radial ball bearing. In this embodiment, the radialball bearing is radially arranged between the rotor 320 and the wobbleplate 330; in other words, an outer ring runner of the ball bearing isthe wobble plate 330 per se, and an inner ring runner of the ballbearing is the rotor 320 per se.

Various examples illustrated in the above may be arbitrarily andsuitably combined, and it has been demonstrated in practice that, a mostpreferable form of combination is: a thrust washer is provided bothbetween the inner ring contact surface of the second bearing and thesecond surface, and between the outer ring contact surface of the secondbearing and the second peripheral portion, and the third bearing is aradial ball bearing.

It will be easily understood that, the present invention is not limitedto specific examples given by the above described embodiments, and anycombinations and readily conceivable variants of these particularembodiments shall fall into the scope of protection of the presentinvention.

1. A two-way wobble plate compressor, comprising: a cylinder block, thecylinder block having a cylinder bore; a two-way piston capable ofreciprocating within the cylinder bore of the cylinder block; a driveassembly driving the two-way piston, the drive assembly including adrive shaft, a rotor fixedly connected with the drive shaft, and anannular wobble plate fitting with the rotor, the rotor having a centralplane angled to a perpendicular plane of the drive shaft, the centralplane of the wobble plate being coincident with the central plane of therotor, when the drive shaft rotates, the rotor drives the two-way pistonvia the wobble plate to perform reciprocating motion; characterized inthat: the rotor has an inner surface for fitting with the annular wobbleplate, the inner surface including a first inner surface and a secondinner surface, which are oppositely arranged, and a rotor contactsurface arranged between the first inner surface and the second innersurface; the wobble plate is partially encircled within the innersurface of the rotor, and includes respectively a first peripheralportion adjacent to the first inner surface, a second peripheral portionadjacent to the second inner surface and opposite to the firstperipheral portion, and a wobble plate contact surface adjacent to therotor contact surface and arranged between the first peripheral portionand the second peripheral portion; wherein a first bearing is providedbetween the first inner surface and the first peripheral portion, asecond bearing is provided between the second inner surface and thesecond peripheral portion, and a third bearing is provided between therotor contact surface and the wobble plate contact surface.
 2. Thetwo-way wobble plate compressor according to claim 1, wherein an innerring contact surface and an outer ring contact surface of said firstbearing are respectively in contact with the first inner surface and thefirst peripheral portion; an inner ring contact surface and an outerring contact surface of said second bearing are respectively in contactwith the second inner surface and the second peripheral portion; and aninner ring contact surface and an outer ring contact surface of saidthird bearing are respectively in contact with the rotor contact surfaceand the wobble plate contact surface.
 3. The two-way wobble platecompressor according to claim 1, wherein a thrust washer is providedbetween the inner ring contact surface of said first bearing and saidfirst inner surface, and/or between the outer ring contact surface ofsaid first bearing and said first peripheral portion; and a thrustwasher is provided between the inner ring contact surface of said secondbearing and said second inner surface, and/or between the outer ringcontact surface of said second bearing and said second peripheralportion.
 4. The two-way wobble plate compressor according to claim 2,wherein said first bearing and second bearing each is one of a needleroller thrust bearing, a roller pin thrust bearing, a double row needleroller thrust bearing, a double row roller pin thrust bearing, and aconical roller thrust bearing.
 5. The two-way wobble plate compressoraccording to claim 2, wherein said third bearing is one of a radialneedle roller bearing, a radial roller pin bearing, or a radial ballbearing.
 6. The two-way wobble plate compressor according to claim 2,wherein a thrust washer is provided between the inner ring contactsurface of said second bearing and said second surface, and between theouter ring contact surface of said second bearing and said secondperipheral portion, and said third bearing is a radial ball bearing. 7.The two-way wobble plate compressor according to claim 1, wherein saidtwo-way piston includes two socket portions, two hemispherical slidingshoes are provided within the two socket portions for interacting withthe first peripheral portion and the second peripheral portion of saidwobble plate, respectively.
 8. The two-way wobble plate compressoraccording to claim 1, wherein said rotor includes a first annular flangeand a second annular flange, and the first annular flange and the secondannular flange are fastened together via a nut and said drive shaft. 9.The two-way wobble plate compressor according to claim 3, wherein saidfirst bearing and second bearing each is one of a needle roller thrustbearing, a roller pin thrust bearing, a double row needle roller thrustbearing, a double row roller pin thrust bearing, and a conical rollerthrust bearing.
 10. The two-way wobble plate compressor according toclaim 3, wherein said third bearing is one of a radial needle rollerbearing, a radial roller pin bearing, or a radial ball bearing.
 11. Thetwo-way wobble plate compressor according to claim 3, wherein a thrustwasher is provided between the inner ring contact surface of said secondbearing and said second surface, and between the outer ring contactsurface of said second bearing and said second peripheral portion, andsaid third bearing is a radial ball bearing.